A light measurement apparatus, by means of which the combination of a light source and a light guide apparatus such as an optical cable is measured, is known, for example, from U.S. Pat. No. 5,115,126. In the case of this test device for endoscope equipment, the light which is emitted from a light source is supplied to a light sensor arrangement having two sensors, partially directly and partially indirectly, that is to say via the light guide apparatus. The detection results of the two sensors are related to one another and are evaluated in order to make it possible to ensure correct operation of the endoscope there.
Numerous versions of light measurement apparatuses have become known. By way of example, U.S. Pat. No. 5,471,129 has already disclosed a calibration apparatus for the light curing appliance there, which is intended to prevent only partial curing of the dental restoration product to be polymerized as a result of an inadequate amount of light being emitted. CA 2 263 269 discloses the calibration of a light curing appliance, in which the electrical parameters of the light source are used for calibration.
Finally, U.S. Pat. No. 5,147,204 discloses a light power detector being fitted to a light curing appliance, and being connected to an evaluation circuit. In this solution, a signal is emitted only when the light power is greater than a predetermined threshold value.
Furthermore, it has already been proposed for a sensor to be provided which has a smaller diameter than the light guide apparatus and its light outlet area. The aim of this is to allow light to be measured without any difference for all possible diameters of light guide apparatuses. This has the disadvantage that, in the case of an optical waveguide with a relatively large light diameter, only a relatively small percentage of the emitted light power is detected. This solution is therefore suitable only for light curing appliances whose diameter is essentially the same as that of the optical waveguide.